plasma glucose levels with dexamethasone as adjuvant to interscalene block

Conditions: Shoulder Pain; Injury of Shoulder Region; Disorder of Shoulder; Disorder of Rotator Cuff; Disorder of Tendon of Biceps

Summary: the purpose of this study is to determine the finger blood glucose (sugar) when dexamethasone is added to a local anesthetic for a shoulder nerve block procedure. the investigators hypothesize that there is no increase in plasma glucose when 8 mg of dexamethasone is used as an adjuvant with local anesthetic to interscalene regional anesthesia. by performing finger stick blood glucose measures pre/peri and post operatively the investigators will be able to determine if any such increase exists.

patients receiving regional anesthesia for orthopedic surgeries are provided with significant pain relief in the post-operative period. dexamethasone as an adjuvant to local anesthetic has been shown to provide increased duration of block without adverse effects. use of steroids as adjuvants are restricted to non-diabetics due to concern for increased plasma glucose from systemic absorption. the investigators hypothesize that there will be no difference(increase) from patient baseline(preoperative plasma glucose) in plasma glucose levels up to 4 hours post nerve block in patients who receive 8 mg of dexamethasone used as an adjuvant with local anesthetic to interscalene regional anesthesia. research has demonstrated the safety and efficacy of dexamethasone as an adjuvant to local anesthetic in peripheral nerve block. currently there are no studies which document any plasma glucose effects(or lack of effects) from dexamethasone used as an adjuvant to regional anesthesia. currently dexamethasone is used clinically off label by anesthesiologists as an adjuvant in association with local anesthetic for nerve block anesthesia. once studies are completed, the investigators hope to allow diabetics to also receive the prolongation of pain relief associated with the use of steroid as an adjuvant. in addition, the increased educational and pharmacological data gleamed from the data can potentially be utilized for future studies with dexamethasone utilized perineurally.

Eligibility criteria:
inclusion criteria: * asa 1 or asa 2 male or female non pregnant patients undergoing elective shoulder arthroscopy for surgical repair. exclusion criteria: * severe lung disease * contralateral diaphragmatic paralysis * coagulopathy * pregnancy * pre-existing neuropathy involving the surgical limb * systemic use of corticosteroids for 2 weeks or longer within 6 months of surgery * chronic opioid use (30 mg oral oxycodone equivalent per day) * diabetes i or ii * diagnosis of "pre-diabetes" * currently prescribed any of the oral glucose medications :sulfonylureas, meglitinides, biguanides, thiazolidinediones, alpha-glucosidase inhibitors, or dpp-4 inhibitors.

Keywords: blood glucose bupivacaine interscalene nerve block regional anesthesia pain blockade arthroscopic surgery arthroscopic rotator cuff repair dexamethasone anti-inflammatory agents therapeutic uses physiological effects of drugs glucocorticoids anesthetics, local anesthetics sensory system agents adjuvants, anesthesia anesthesiology injections adult analgesia/methods brachial plexus/drug effects brachial plexus/surgery brachial plexus/ultrasonography bupivacaine/administration & dosage dexamethasone/administration & dosage drug therapy, combination female humans male nerve block/methods pain, postoperative/etiology pain, postoperative/prevention & control prospective studies time factors